hig-gins



(No Model.) 2'Sheet sSheet 1. J. J. HIGGINS.

PHOTO-GHRONOGRAPH.

No. 351,108. Patented Oct. 19, 1886.

WITNESSES: E INVENTOB: 5 7% 5 T W -zwz BY Meow ATTORNLg w PETERS Fhom Lllhc mp c.

2 Sheets-Sheet 2.

(No Model.)

J. J. HIGGINS.

PHOTO-GHRONOGRAPH.

- No. 351,108. Patented Oct. 19, 1886.

INVENTOB BY %w WITNESSES ATTORNEYS UNITED STATES PATENT OFFICE.

JOHN J. HIGGINS, OF NFBV YORK, N. Y., ASSIGNOR TO E. & H. T. ANTHONY. & (30., OF SAME PLACE.

PHOTO-CHRONOGRAPH.

SPECIFICATION forming part of Letters Patent No. 351,108, dated October 19, 1886.

Application filed February 12, 1886. Serial No. 191,757. (Xo model.)

To all whom it may concern.-

Be it known that I, JOHN .T. I-IIGG'INS, of the city, county, and State of New York, have invented a new and useful Improvement in Photo-Ohronographs, of which the following is a specification, reference being had to the annexed drawings, forming a part thereof, in which Figure 1 is a front elevation. Fig. 2 is a front elevation with the dial and easing removed. Fig. 8 is a vertical transverse section taken on line or 00 in Fig. 1. Fig. at is a detail view of the photographic record of the photochronograph. Figs. 5 and 6 are detail perspective views.

Similar letters of reference indicate corresponding parts in the different figures of the drawings.

In the practice of photography no convenient and reliable method for determining the period of exposure of sensitive plates through the drop-shutter has been available.

The object of my invention is to provide a simple, inexpensive, and efficient chronograph for determining the period of exposure of any dropshutter or for making a permanent record from which the duration of the exposure may be determined.

My invention consists in a graduated dial and an arm revolving in front of the dial and carrying a light-reflectingsurface,and, in combination with the motor employed in driving the arm, of a slow-moving calibrating-wheel whose period of rotation bears a fixed relation 3 5 to that of the arm, and an audible signal operated once during each rotation of the slowmoving wheel to facilitate calibration.

The motor A, which drives the arm and the slow-moving wheel, in the present case is a 0 spriug-n1otor formed of the wheels 13 O D, secured to arbors (t b c, the arbor a being connected with the driving-spring,the first wheel, B,Ineshing into the pinion d on the arbor b, the wheel 0 meshing into the pinion e on the arbor 0. The wheel I) on the arbor o meshes into a pinion, f, on the arbor y, and the arbor g carries a fan, It, for controlling the movement of the spring-motor.

Upon an arbor, i, journaled in the motorframe, is secured a pinion, j, which is driven by the wheel B. The arbor i also carries a brake-wheel, 7:, which is pressed by a brakcspring, Z, secured to astud, m, journaled in a support attached to the back of the chronograph-casing, as clearly shown in .Fig. 5. Upon the stud an, outside of the casing, is secured an arm, or, provided with series of holes 0 for receiving a pin entering holes in the cats ing,for retaining the arm n in any desired po sition, thus holding the brakespring Z under more or less tension.

Upon an arbor, ;,jonrnalcd in the motorframe and projecting through the dial E upon the front of the chronograph casing, is secured a pinion, q,.which is engaged by the spur-wheel D. To a bracket, a, secured to the back of the chronograph-casing is pivoted a lever, 8, having at one end a right-angled arm,

t, which reaches into the movement in position to touch the arbor p when the lever is moved in the manner presently to be described, as shown in Fig. 6. To the opposite and shorter end of the lever is secured a plate, a, and a rod, o, extends through the front of the casing in position to be touched by the bezel w when itis closed down over the dial E, so that when the bezel w is closed the rod a will push against the plate u on the end of the lever s and bring its right-angled end 15 into frictional contact with the arbor 12, thus arresting the movement of the motor, and when the bezel w is opened, the rod '0 being relieved of pressure, the angled end t of the lever s will be carried away from the arbor p by a spring, a, secured to the back of the chronograph-casing and pressing against the back of the shorter arm of the lever.

011 a support, I), secured to the back of the casing, is pivoted a bell-hammer, c, in position to strike the bell d, and to the arm of the bellhainmer is secured a wire, 6, which extends into the motor in position to be engaged by the pin f, carried by the brakewheel 7;, once during each revolution of the brake-wheel 9 5 The dial E, which is placed in the front of the casing and covers all the moving parts of the apparatus excepting the arm F, has a circular opening, 9, opposite and concentric with the arbor 1', and to the arbor r is secured a no larger graduations are subdivided by short rathereof, at right angles, and embracing thedial lines Z, extending from the periphery of the dial a short distance toward the center thereof,

Thearm F is carried by a boss, m, received on the arbor p, and consists of a straight bar of metal having parallel edges. Upon one end of the arm F is placed a plate, G, provided with spring-clips n, projecting from the back sides of the arm F.

The dial E is preferably made black, and the grad nations thereon are formed of white lines, and the outer surface of the plate G is also white.

Any motor which will impart a continuous uniform rotary motion to the bar Fwill answer the purposes of my invention. Therefore I do not limit or confine myself to the exact form of 'motor herein shown and described.

The method of using myimproved chronograph is as follows: The bezel w is opened, releasing the movement in the manner described, allowing the wheel h and the arm F to revolve. In the present case the gearing of the motor is so proportioned that the arm F makes five hundred and twenty revolutions while the wheel h makes one revolution, and the user of the chronograph determines the time required to complete five hundred and twenty revolutions of the arm F by timing the interval between two successive strokes of the hell by means of any convenient time-piece. The operator then knows the rate of rotation of the arm F, so that when the plate G, carried by the arm F,'is photographed during its rotation the image produced upon the sensitive photographic plate may be utilized to determine the duration of the exposure of the plate. If, for example, the arm F makes five hundred and twenty revolutions in one minute,

, it will make 8.66 revolutions in one second;

and if the image produced on the plate covers one-fifth of the circle over which the plate G, carried by the arm, travels it indicates that the image has been produced in 0.22 of a second, as the time required for one revolution of the arm F is approximately .11 of a second.

In the part of a photograph of a dial and the moving plate G, (shown in Fig. 4,) I represents the curved light streak produced on the sensitive plate by light reflected from the plate G while the chronograph is in motion. It will thus be seen that the light streak produced on the photographic'plate indicates the time of the exposure, and consequently affords a legibio and permanent record of the action of the drop-shutter.

- I have shown in connection with the motor afbn, h, for retarding and regulating its motion; but by proportioning the width of the bar F to the strength of the spring of the motor the fan It may be dispensed with, as the bar F will then act as a regulator to the movement of the motor.

Owing to the facility with which my improved chronograph can be calibrated, no extreme accuracy is required in its construction, so that, if desirable, it may be tested at each operation.

\Vhen it becomes necessary to reduce the velocity of the plate G for slow-working sensitive plates, the plate can he slid along the bar F toward the arbor 1), thus causing it to revolve in a smaller circle; or the speed of the movement may be varied by applying more or less pressure to the brake-wheel k by means of the spring Z. I

By employing an audible signal in connection with the calibrating device greater accuracy is secured than will be possible by merely observing the calibrating-wheel.

Having thus fully described my invention,.

what I claim as new, and desire to secure by Letters Patent, is-

1. In a photo-chronograph, alight-reflecting plate and means for carrying it in a circular path, substantially as herein shown and dcscribed.

2. The combination,in a photo-chronograph, of the rotating arm F and the light-reflecting plate G, adjustably secured to the arm, substantially as herein shown and described.

3. In a photo-chronograph, the combination, with the rotating arm Fand light-reflecting plate G carried thereby, of the calibrating-wheel h, having a rotary motion bearing a fixed relation to the motion of the arm F, substantially as herein shown and described.

4. In a photo-chronograph, the combination, with the rotating arm F, having a lightreflecting surface, of the calibrating-wheelh, having a rotary motion bearing a fixed relation to the motion of the arm F, substantially as described.

5. Ina photo-chronograph, the combination, with the revolving arm F, lightreflecting-plate G carried thereby, of the calibrating-wheel h, and a sound mechanism operated substantially as herein shown and described.

6. The combination, with the rotating arm F and light-reflecting plate G carried thereby, of the graduated dial E, having a dark ground and light graduated lines formed thereon, substantially as herein shown and described.

7. In a photo-chronograph, the combination, with the arm F and light-reflecting plate G carried thereby, of a motor for imparting continuous rotary motion to the arm, substantially as herein shown and described.

8. In a photo-chronograph, the combina tion, with the rotating arm F, light-reflecting shown and described.

9. The combination, with the light-reflecting plate G, arm F, and arbor 17, carrying the same, of the lever 8, having the angled end t, and the rod 1), adapted to be pressed by the bezel when closed over the dial, substantially as and for the purpose specified.

10. In. a photochronograph, the combination, with the motor provided with the wheels B CD, of arbors a Z) c p i, the pinions b, q, and

j, carried by the arbors, the brake-Wheel 7.:

secured to the arbor i, the adjustable brakespring Z, the pinf, projecting from the side of the brakewheel, the bell-hammer c, the bell (Z, the calibrating wheel h, the arm F, and light-reflecting plate G, carried thereby, sub stantially as herein shown and described.

ll. The method of recording the time of exposure of a sensitive photographic plate, consisting in exposing a sensitive photographic plate to a light-reflecting plate revolving 111 front of a graduated dial at a known rate of 20 revolution, developing the plate, and finally calculating the time of exposure by compan ing the length 01' the image of the light-reflecting plate with the length of the path of the light-reflecting plate and the period of its revo- 25 lntion, substantially as herein shown and described.

JOHN J. HIGGINS. \Vitnesscs:

O. Snnewion, EDWD. M. CLARK. 

